The present invention relates to a leader block assembly for a data storage tape cartridge. More particularly, it relates to a leader block assembly including a tape clamp configured to positively engage a leader block for consistently securing a storage tape.
Data storage tape cartridges have been used for decades in the computer, audio, and video fields. The data storage tape cartridge continues to be an extremely popular form of recording large volumes of information for subsequent retrieval and use.
Data storage tape cartridges generally consist of an outer shell or a housing maintaining at least one tape reel assembly and a length of magnetic storage tape. The storage tape is wrapped about a hub portion of the tape reel assembly and is driven through a defined tape path by a separate driving system. The housing normally includes a separate cover and base, the combination of which forms an opening (or window) at a forward portion thereof for allowing access to the storage tape by a read/write head upon insertion of the data storage tape cartridge into a tape drive.
In a reel-to-reel magnetic tape drive, a free end of the storage tape is directed away from the cartridge housing to an adjacent area within the tape device at which the read/write head is located. The free end of the storage tape is typically secured to a leader block assembly to assist in guiding the storage tape from the housing. In particular, the leader block assembly is removably inserted into a drive take-up reel (separate from the data storage tape cartridge), and the storage tape from the cartridge is wound about the take-up reel as data is accessed/recorded from the tape by the adjacent read/write head.
Most leader block assemblies include a leader block and a tape clamp. The leader block provides the requisite features for proper take-up reel engagement, as well as desired attachment to the cartridge housing at the window when not in use. Further, the leader block forms a channel within which the tape clamp is nested, with the free or leading end of the storage tape being secured between the tape clamp and the leader block. Thus, the tape clamp must lock to the leader block to consistently maintain engagement with the storage tape when the leader block assembly is xe2x80x9cpulledxe2x80x9d from the cartridge housing by the tape drive.
A prevailing leader block assembly design achieves the desired interlocking relationship between the tape clamp and leader block by forming locking tabs on opposing sides of the tape clamp. Similarly, the leader block forms slots designed to receive the locking tabs. One example of this technique is illustrated in U.S. Pat. No. 5,303,875, the teachings of which are incorporated herein by reference. Additional features may be incorporated into the leader block assembly to promote alignment between the leader block and the tape clamp. However, the locking tabs are the primary feature used to secure the tape clamp to the leader block.
While viable, the locking tab technique raises certain concerns. In particular, assembly of the tape clamp to the leader block generally entails positioning the tape clamp above the channel and then pressing the two components toward one another. In this regard, the leader block sidewalls (otherwise defining the channel and forming the tab-receiving slots) will, in theory, deflect slightly outwardly along the locking tabs until the tape clamp is located within the channel. At this point, the sidewalls return to a natural the unloaded position, with the locking tabs positioned within the respective slots. Unfortunately, sufficient sidewall deflection may not occur, causing the locking tabs to permanently deform (i.e., exceed their elastic limit or otherwise xe2x80x9ccrushxe2x80x9d) so that upon final assembly, the locking tabs no longer provide desired surface area engagement within the slot. Additionally, interaction between the locking tabs and the leader block does not provide a positive lock or engagement. In particular, the slot engagement surface is non-planar relative to the engagement surface of the locking tab and/or the above-described locking tab deformation prevents uniform engagement from occurring. As a result, the tape clamp may not be uniformly locked to the leader block. Further, control over an overall thickness of the leader block assembly may be difficult to achieve in that a precise position of the tape clamp relative to the leader block can vary depending upon the extent of locking tab deformation. This potential deviation from a desired design parameter may, in turn, lead to handling issues within the cartridge housing and/or the take-up reel.
Current leader block assembly designs are highly sufficient for current data storage tape cartridge applications. However, the potential inconsistencies in mounting of the tape clamp to the leader block may give rise to future complications. As such, a need exists for a leader block assembly adapted to positively secure a storage tape on a uniform basis.
One aspect of the present invention relates to a leader block assembly for holding an end of a storage tape. The leader block assembly includes a leader block, a tape clamp, and an elastomeric member. The leader block defines a leading section and a trailing section forming a channel defined by opposing sidewalls extending from a base. In this regard, each of the opposing sidewalls forms a lip opposite the base, with each lip having an under surface. The tape clamp is nested within the channel and includes a bottom surface, opposing sides, and at least one cantilevered leg positioned at each of the opposing sides, respectively. In this regard, each of the legs extends upwardly relative to the bottom surface. Finally, the elastomeric member is disposed between the leader block and the tape clamp, and is provided to bias the tape clamp to a locked state in which the legs engage the under surface of the respect lips. By providing cantilevered legs, assembly of the tape clamp to the leader block does not result in a permanent deformation of the assembly components, thereby facilitating a positive engagement between the tape clamp and the leader block. In one preferred embodiment, each of the legs extends in an angularly outward fashion, thereby defining a free end that is transversely offset from a corresponding fixed end.
Another aspect of the present invention relates to a data storage tape cartridge. The data storage tape cartridge includes a housing, at least one tape reel assembly, a storage tape, and a leader block assembly. The housing defines an enclosure. The tape reel is disposed within the enclosure and includes a hub. The storage tape is wound about the hub. Finally, the leader block assembly is secured to a leading end of the storage tape. In this regard, the leader block assembly includes a leader block, a tape clamp, and an elastomeric member. The leader block defines a leading section and a trailing section, with the trailing section forming a channel. In particular, the channel is defined by opposing sidewalls extending from a base. Further, each of the sidewalls forms a lip opposite the base, with each lip having an under surface. The tape clamp is nested within the channel and includes a bottom surface, opposing sides, and at least one cantilevered leg positioned at each of the opposing sides, respectively. In this regard, each leg extends upwardly relative to the bottom surface. Finally, the elastomeric member is disposed between the leader block and the tape clamp for biasing the tape clamp to a locked state in which the legs positively engage the under surface of the respective lip. In one preferred embodiment, the leading end of the tape is affixed between the elastomeric member and the leader block.
Yet another aspect of the present invention relates to a method of assembling a leader block assembly for securing a leading end of a storage tape. The method includes providing a leader block forming a channel defined by opposing sidewalls extending from a base, each of the sidewalls forming a lip opposite the base and having an under surface. A tape clamp is provided that includes a central body defining a bottom surface and opposing sides. Further, the tape clamp includes at least one cantilevered leg extending upwardly relative to the bottom surface at each of the respective sides. An elastomeric member is further provided. The elastomeric member is positioned at the bottom surface of the tape clamp. The tape clamp is positioned adjacent the channel. The tape clamp is directed into the channel. In particular, the bottom surface of the tape clamp is directed toward the base of the leader block. In this regard, the legs deflect inwardly along the lips from an unloaded or free position as the tape clamp is directed into the channel. A final assembly position is achieved in which the tape clamp is nested within the channel and the legs elastically return to the unloaded position. In the final assembly position, the elastomeric member biases the tape clamp to a locked state in which the legs engage the under surface of the respective lip. With this technique, and unlike previous designs, the tape clamp components, and in particular the cantilevered legs, are not permanently deformed such that a positive lock is achieved between the tape clamp and the leader block.